1======================
2LLVM 3.4 Release Notes
3======================
4
5.. contents::
6    :local:
7
8.. warning::
9   These are in-progress notes for the upcoming LLVM 3.4 release.  You may
10   prefer the `LLVM 3.3 Release Notes <http://llvm.org/releases/3.3/docs
11   /ReleaseNotes.html>`_.
12
13
14Introduction
15============
16
17This document contains the release notes for the LLVM Compiler Infrastructure,
18release 3.4.  Here we describe the status of LLVM, including major improvements
19from the previous release, improvements in various subprojects of LLVM, and
20some of the current users of the code.  All LLVM releases may be downloaded
21from the `LLVM releases web site <http://llvm.org/releases/>`_.
22
23For more information about LLVM, including information about the latest
24release, please check out the `main LLVM web site <http://llvm.org/>`_.  If you
25have questions or comments, the `LLVM Developer's Mailing List
26<http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev>`_ is a good place to send
27them.
28
29Note that if you are reading this file from a Subversion checkout or the main
30LLVM web page, this document applies to the *next* release, not the current
31one.  To see the release notes for a specific release, please see the `releases
32page <http://llvm.org/releases/>`_.
33
34Non-comprehensive list of changes in this release
35=================================================
36
37.. NOTE
38   For small 1-3 sentence descriptions, just add an entry at the end of
39   this list. If your description won't fit comfortably in one bullet
40   point (e.g. maybe you would like to give an example of the
41   functionality, or simply have a lot to talk about), see the `NOTE` below
42   for adding a new subsection.
43
44* The regression tests now fail if any command in a pipe fails. To disable it in
45  a directory, just add ``config.pipefail = False`` to its ``lit.local.cfg``.
46  See :doc:`Lit <CommandGuide/lit>` for the details.
47
48* Support for exception handling has been removed from the old JIT. Use MCJIT
49  if you need EH support.
50
51* The R600 backend is not marked experimental anymore and is built by default.
52
53* APFloat::isNormal() was renamed to APFloat::isFiniteNonZero() and
54  APFloat::isIEEENormal() was renamed to APFloat::isNormal(). This ensures that
55  APFloat::isNormal() conforms to IEEE-754R-2008.
56
57* The library call simplification pass has been removed.  Its functionality
58  has been integrated into the instruction combiner and function attribute
59  marking passes.
60
61* Support for building using Visual Studio 2008 has been dropped. Use VS 2010
62  or later instead. For more information, see the `Getting Started using Visual
63  Studio <GettingStartedVS.html>`_ page.
64
65* The Loop Vectorizer that was previously enabled for -O3 is now enabled for
66  -Os and -O2.
67
68* The new SLP Vectorizer is now enabled by default.
69
70* llvm-ar now uses the new Object library and produces archives and
71  symbol tables in the gnu format.
72
73* ... next change ...
74
75.. NOTE
76   If you would like to document a larger change, then you can add a
77   subsection about it right here. You can copy the following boilerplate
78   and un-indent it (the indentation causes it to be inside this comment).
79
80   Special New Feature
81   -------------------
82
83   Makes programs 10x faster by doing Special New Thing.
84
85
86External Open Source Projects Using LLVM 3.4
87============================================
88
89An exciting aspect of LLVM is that it is used as an enabling technology for
90a lot of other language and tools projects. This section lists some of the
91projects that have already been updated to work with LLVM 3.4.
92
93
94Additional Information
95======================
96
97A wide variety of additional information is available on the `LLVM web page
98<http://llvm.org/>`_, in particular in the `documentation
99<http://llvm.org/docs/>`_ section.  The web page also contains versions of the
100API documentation which is up-to-date with the Subversion version of the source
101code.  You can access versions of these documents specific to this release by
102going into the ``llvm/docs/`` directory in the LLVM tree.
103
104If you have any questions or comments about LLVM, please feel free to contact
105us via the `mailing lists <http://llvm.org/docs/#maillist>`_.
106
107